1. Field of the Invention
The invention is related to the field of communications and, in particular, to systems and methods that validate caller ID information to protect a called party from caller ID spoofing.
2. Statement of the Problem
Service providers typically offer a caller ID service to their subscribers. A caller ID service is an intelligent network service that provides caller ID information, such as a calling party's directory number and name, to the called party's telephone equipment during the ringing signal. The communication network typically provides the caller ID information between the first and second rings of a call. The called party's telephone equipment then displays the caller ID information to the called party.
One problem with present caller ID services is that the caller ID information may not be valid, which is often referred to as caller ID spoofing. Caller ID spoofing is the practice of causing a communication network to display a directory number and/or name on the called party's telephone equipment which is not that of the actual originating station. For example, if a call is placed from the directory number NXX-XXX-0000, caller ID spoofing may be used so that the directory number NXX-XXX-9999 is displayed on the called party's telephone equipment. The motivation behind caller ID spoofing may be unlawful or mischievous, which exacerbates the problem and diminishes the value of the caller ID service.
There are presently companies that offer caller ID spoofing services for a fee. One such service uses a prepaid calling card. To use the caller ID spoofing service, a calling party dials a toll free number on the prepaid calling card and enters a PIN. The calling party then enters the directory number they want to call and the directory number they want displayed on the telephone equipment of the called party. The caller ID spoofing service then bridges the call and the called party's telephone equipment displays the false directory number as entered by the calling party. Other caller ID spoofing services use a web-based interface for spoofing VoIP calls. Because of the possibly harmful effects of caller ID spoofing, it is desirable to protect called parties against caller ID spoofing.